1. Field of the Invention
The present invention relates to an apparatus for reproducing digital audio signals. More specifically, the present invention relates to an apparatus and a method for digital-mixing two sound sources, and performing both audio-outputting and encoding-storing of the digital-mixed sound sources.
2. Description of the Related Art
FIG. 1 is a schematic block diagram of a digital audio player according to prior art. Referring to FIG. 1, the digital audio player includes a central processing unit (CPU) 120, a codec unit 110, a memory unit 130, and an audio output input 140. The playing and recording processes using the conventional digital audio player shown in FIG. 1 are illustrated in FIGS. 2 and 3.
In the playing process, the CPU 120 reads out the digital sound source from the memory unit 130 by the user's manipulation, in step S11, and performs decoding, in step S12. The sound sources stored in the memory unit 130 are digital audio signals compressed in different forms.
The digital signals decoded by the CPU 120 are converted to analog signals at the codec unit 110 and output through the audio output unit 140 such as a speaker or the like, in step S13.
In the recording process, the codec unit 110 transfers audio signals externally input through an audio input unit such as a microphone, in step S21.
The CPU 120 encodes the digital signal data from the codec unit 110 according to a defined method, in step S22, and stores them in the memory unit 130.
In the above description, the codec unit performs analog-to-digital or digital-to-analog signal conversions. Namely, it converts analog audio signals externally input through a microphone into digital signals, or digital signals from the CPU into analog signals in the form of audible sound to be output through the output unit such as a speaker.
As described above, the conventional digital audio player performs a digital audio playing operation and a recording operation separately in a different procedure.
The reason for this is that the CPU 120 has no function of processing the two events in a simultaneous manner. Accordingly, there is a demand for a digital audio player or a playing method thereof for performing both playing and recording operations with one digital audio player.
It is therefore an object of the present invention to provide a digital audio player and a playing method thereof for digital-mixing two sound sources and performing both audio outputting and recording.
It is another object of the present invention to provide a digital audio player and a playing method thereof for performing both decoding and encoding of digital audio sources.